In an offset pen structure for rapid assembling, a holding portion is disposed, and an offset portion extends from the side at the front part of the holding portion, and a writing device base is disposed at the end of the offset portion, wherein the offset portion together with the holding portion has a hollow passage formed therein such that the hollow passage has an opening formed at the front end of the offset portion; the opening being used for mounting a recording device and covered by a lid; the writing device base is disposed at the front end of the lid; a fixing portion is disposed at the rear end of the lid, the fixing portion being fixed at the end of the offset portion to fix and position the writing device base on the holding portion; and further a cap is disposed on the writing device base to form a protection, with a clip disposed on the side thereof, the clip being used to be inserted into a pocket of the user for convenient carry.